VP 5,7 GSI starting problems(fuel pumps not active on crank)

[Antti84]

I could use some help with getting my volvo penta started.
I am getting spark,I am getting fuel for the 1-2seconds when the fuel pumps are priming with some fuel.
I have measured that the fuel pump connectors are getting 12V for the first two seconds,then it stops.
So during crank it's not feeding the engine with gas any more.

I have measured the relays,gone thru wiring,tried to ground the oil press switch but nothing happens.I have also tested the fuel pumps with12v and they are spinning.
Feels like I have checked everything that manages the fuel supply

Any ideas?

 

[Silverbullet555]

Check your kill switch though if the pumps are running for a bit I doubt that.

On my VP, the fuel pumps run 10 seconds or so to pressurized the system.

Have you checked your fuel pressure on the rail?

 

[Antti84]

I have checked the kill switch..the pumps are getting 12v for max 2seconds.I have measured that with a multimeter from the fuel pump harness

I have not measured the fuel press because I would like the pumps to stay on during crank to begin with...

This model has two pumps,one on top of the fuel filter and one at the back of the engine.
I am also getting over 40psi of oil press during cranking

One other thing I noticed was that the rpm gauge is not working at all.not sure if this has anything to do with this problem though.

I just bought the boat so I dont have any previous experience on how this engine has behaved earlier.

 

[Antti84]

No Title

Does anyone have electrical wiring diagram of this engine? The engine is a 5,7litres GSI.I have attached the serial plate to verify the engine type

 

[mklearl]

I don't have a manual in front of me but the pump will come on for a couple of seconds to prime. The pumps need to know that the engine is running so they Don't continuously pump fuel if not cranking. I believe this is done from the alternator cranking. Look for a green? wire coming off the alternator to the fuel pump relay. Again I'm not positive on the color as I don't have the diagram in front of me. But it sounds like the wire from the alternator to the pump isn't telling the pump that the motor is cranking... therefore no power to the pump when cranking.

 

[Antti84]

No Title

 

[Antti84]

Thanks for your reply.I have measured 12v from the fuel pump/ignition relay,however I have not measured it during crank.Iy makes me a bit confused how the 12v would disappear from the alternator wire during cranking?

I am planning to check the ECM ground wires next time I go next to the boat.

 

[Antti84]

I tried jumping the fuel pump relay today with +12v (30->87) and guess what, the pumps went on for two seconds and stopped...
This would indicate that I have something wrong with my grounding...?
I removed the gnd cables at the back of the engine.I will press new crimps for these cables..I will also check the grounding cables from the ecm when I have proper measuring equipment.

Any other ideas on the troubleshooting?

 

[mklearl]

http://forums.iboats.com/forum/engi...nboard-gas-engines-outdrives/414938-need-help

Read post #9. This is for a 4.3gl and is probably different than the diagram but troubleshooting the electrical portion should be the same. Your pump is good. I'm sticking to my theory that for some reason the fuel pump doesn't "think" that your engine is cranking. Bad diode or wiring to the alternator.

I'm not sure why a bad grounding would cause it to run and stop. The pump is supposed to run for 2 seconds and stop to prI'm the system. It only continues to run if the engine is crankin. If you supply 12v directly to the pump it will continuously run. Troubleshoot with the procedures in post 9 on the link above.

 

[Antti84]

Thanks for your response..

I followed the troubleshooting steps on #9 and measured between GND and Alternator diode/Ignition switch.
During crank i measured 12V.I was happy and thought that I had found the problem(relay)
I went and bought a relay,installed it...
Cranked and it did not start...

Starting to feel a bit anxious about this now..

 

[Antti84]

Does someone have any other ideas where to continue troubleshooting?
Where is the engine getting its rpm information from?

 

[mklearl]

Do you have 12v at the pump when cranking? I know you do when you turn the key on for 2 seconds. Bit at cranking do you?

 

[mklearl]

Do the last test on post 9 from the link. Possibly the diode on the ignition wire if your relay is good.

 

[Antti84]

Thanks!

I did the last test and tested to measure on gnd and ignition/alternator and it showed 12V.
Do you know if the diode from ignition wire is located behind the dash or in the engine

I will recheck tomorrow if the pumps get 12v during crank

 

[alldodge]

I'm seeing a bit of a conflict in terms. Post 1

I have measured that the fuel pump connectors are getting 12V for the first two seconds, then it stops

In post 3

One other thing I noticed was that the rpm gauge is not working at all.not sure if this has anything to do with this problem though.

In post 8

I tried jumping the fuel pump relay today with +12v (30->86) and guess what, the pumps went on for two seconds and stopped...

Connection to power pump would be 30 and 87

In post 14

I will recheck tomorrow if the pumps get 12v during crank

The motor needs spark and I have not heard the this has been checked. Measure the voltage at the coils purple wire. If you get 12V while ON and when cranking, remove a plug wire and see if you can get spark to ground.

 

[mklearl]

Thanks!

I did the last test and tested to measure on gnd and ignition/alternator and it showed 12V.
Do you know if the diode from ignition wire is located behind the dash or in the engine

I will recheck tomorrow if the pumps get 12v during crank

I do not know where the diode is located. I had a similar problem on a 5.0gi and this was information that I found. I never got that far as mine ended up being a bad pump. Verify spark as all dodge stated. 30 to 86 can't be jumped. You can verify power there but that is just a 12v pisitive and negative terminal. 30 to 87 should turn the pump on. Again read that post and follow. Is this a tbi or mpi?

 

[mklearl]

I'm seeing a bit of a conflict in terms. Post 1


In post 3


In post 8


Connection to power pump would be 30 and 87

In post 14


The motor needs spark and I have not heard the this has been checked. Measure the voltage at the coils purple wire. If you get 12V while ON and when cranking, remove a plug wire and see if you can get spark to ground.

You haven't verified fuel either. Just because the pump comes on for 2 seconds doesn't mean it has fuel. It just means the pump is spinning for 2 seconds. What is the year and full model number of your engine?

 

[Antti84]

Thanks for your response.The engine is a 5,7GSI from 1999 with TBI.
I apoligise for the typo,I jumped 30 and 87 which made the pumps go on for two seconds and then stop.

I have measured spark with a spark tester that you plug between the plug and cable.

I will re-check that the pumps are not getting power during cranking.

 

[mklearl]

Great. Take off the flame arrestor and look to see if the injectors are spraying fuel into the throttle body for 2 seconds when you hear the pump running. My guess is no. Which pump do you hear running? The one by the filter or the one on the back of the engine? Do you hAve a schrader valve on the fuel line from the high pressure pump to the throttle body? If so... check pressure there when the key is turned on. Check that and let me know. Verify which pump you are actually hearing and if you have fuel spraying out of the injectors for 2 seconds... I have a couple theories!

 

[Antti84]

No Title

Thanks mkearl.

Your help is much appreciated.

I have tested that both pumps are spinning for two seconds by removing the plug on one of the pumps and turn the key to hear if te other pump is working.
So I have verified that both pumps are running for two seconds.
I ave not however looked visually to confirm that the fuel is spraying fuel into the TB.I will check that.Could you shed a light why you think that there is no fuel spraying into the TB?

Ihave attached a picture,I think that one of the lines is for measuring the pressure (schroeder)

You would not happen to remember what thread it is on this valve,so i can go and buy a gauge that fits there.

Thanks again!